Inline type triple electron gun assembly

ABSTRACT

An in-line type triple electron gun assembly comprising three electron gun members which are juxtaposed in the common plane and each of which includes a plurality of electrodes spaced apart along its axis, respective corresponding electrodes of three electron gun members being connected by metal supporting strip members which are fused to insulating supporting rods between respective gun members so as to form an integral assembly.

United States Patent Inventors Asahide Tsuneta Kawasaki; Shinichi Sawagota, Tokyo, both 01, Japan App]. No. 36,985 Filed May 13, 1970 Patented Sept. 7, 1971 Assignee Tokyo Shibaura Electric Co., Ltd.

Kawasaki-511i, Japan Priority May 16, 1969 Japan INLINE TYPE TRIPLE ELECTRON GUN ASSEMBLY 4 Claims, 7 Drawing Figs.

us. cu 313/70 C, 3 13/251 Int. Cl ..H0lj 29/50,

H01j 29/02, n01,- 19/42 [50] Field oi Search 313/69 C, 70 C, 77, 78, 82, 82 BF [56] References Cited UNITED STATES PATENTS 2,859,378 11/1958 Gundert et al 315/13 3,434,819 3/1969 Merchant et al 65/155 Primary Examiner-Robert Segal Attorney- Flynn & Frishauf ABSTRACT: An in-line type triple electron gun assembly comprising three electron gun members which are juxtaposed in the common plane and each of whichincludes a plurality of electrodes spaced apart along its axis, respective corresponding electrodes of three electron gun members being connected by metal supporting strip members which are fused to insulating supporting rods between respective gun members so as to form an integral assembly.

PATENTEU SEP 719. 1

SHEET 1 BF 2 l52c 153c PATENTEU SEP 7 IQYi 3, 03 829 sum 2 OF 2 INLINE TYPE TRIPLE ELECTRON GUN ASSEMBLY BACKGROUND OF THE INVENTION This invention relates to a triple electron gun assembly, moreparticularly of the inlet type.

It is well known that theinlet triple electron gun assembly comprises three electron gun members and a convergence electrode with the gun members juxtaposed in a common plane so that electron beams emanated from respective gun members will cross each other at an opening of the shadow mask contained in a color television receiving tube. The prior art gun assembly is fabricated by arranging at a definite spacing a plurality of cup-shaped electrodes each having two projections extending on opposite sides, securing projections ex- ..tending in the same side to insulating supporting rods of glass by fusion to form electron gun members and then securing together these gunmembers into a unitary structure by weld- :ing. For this reason, each electron gun member requirestwo supporting rods, so that the resulted electron gun assembly t requires a total of six supporting rods. This increases the size of the entire assembly and such construction cannot be used fora cathode ray tube having a neck of small diameter. Even when the assembly is incorporated into a cathode ray tube having a large-diameterneck, such a construction requires a high deflection voltage. Further, the accuracy of the assembly is low because it requirestwo steps of fabrication, namely, the step of forming theelectrongun members and the step of assembling these gunmembers. As a consequence, when the as- SUMMARY OF THE INVENTION According tothis inventionthere is provided an in-line type triple electron gun assembly comprising three electron gun members juxtaposed in the common plane. Each of the electron gun'member comprises a plurality of electrodes spaced 1 apart along its axis and corresponding electrodes of three elecutron gun'members are securely connected to each other by supporting strip metal members. Corresponding electrodes of the same potential are supported by first supporting strip members while corresponding electrodes atdifferent potentials are supported by second supporting members. Each of thefirst supporting members is formed by a single metal strip whereas each second supporting strip member includes three 1 separate metalsegments each engaging a different electrode.

The first and second supporting strip members are provided wwith outwardly extending projections at portions between adjacent electron gun members and these projections arefused to supportingrods of glass. There are total of four supporting rods. Three electron gun members fabricated in this manner are connected to a convergence electrode having at its bottom three perforations for passing electron beams travelling through electron gunmembers. With this construction, it is possible to decrease the number of insulating supporting rods and hence reduce the overall size of the triple electron gun assembly so that the assembly can be incorporated into the 1 smaller diameter neck of a cathode ray tube.

' BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a side elevationof a'tripleelectron gun assembly embodying this invention;

FIGJZ' is a longitudinal sectional view of the electrodes as shown in FIG. 1 arranged in a prescribed position;

FIG. 3A is an enlarged perspective view of a first supporting strip member utilized in the assembly shown in FIG. 1;

DESCRIPTION OF THE PREFERRED EMBODIMENT A construction and a method of fabricating a triple electron gun assembly embodying this invention will now be described with reference to the accompanying drawings.

A triple electron gun assembly 10 shown in FIG. 1 comprises three electron gun members 11a, 11b and disposed side by side with their axes contained in a common plane, sup

porting means including first and second insulating strip metal members 12 and 13 for interconnecting electron gun members 11a, 11b and 110 at a predetermined spacing, insulating supporting rods 14 to which supporting strip members 12 and 13 are rigidly secured, and a convergence: electrode 15 secured to oneend of the electron gun members.

More particularly, the electron gun member 11a, as viewed in FIG. 2 comprises a first grid electrode 16a, a second grid electrode 17a, a third grid electrode 118a a fourth grid electrode 19a and a fifth grid electrode 20a, each formed into a cup-shaped configuration having aperforation at the centerof the bottom to pass an electron beam and said grid electrodes are arranged successively with their axes coinciding with'a straight center line Sa. Similarly, the central and right-hand electron gun members are comprised] by corresponding first grid electrodes 16b, 160, second grid electrodes 17b, 17c,

third grid electrodes 18b, 18c, fourth grid electrodes 19b, 19c and fifth grid electrodes 20b, 200, which are successively arranged along center lines Sb and Sc, respectively. Three electron gun members 11a,11b, and 110 are disposed side byside with their axes Sa, Sb and Se contained! in a common plane but with axes Sa and Sc of electron gun members 11a and 11c inclined at an. angle 0 with respect to the axis Sb of theelectron gun assembly 11b so that spacings between laterally adjacent grid electrodes gradually decrease from the first grid electrodes 16a, 16b and toward the fifth grid electrodes 20a, 20b and 200, thus causing axes Sa, Sb and Se to cross each other at a perforation of a shadow mask disposed in a color television receiving tube, not shown.

To mutually secure respective corresponding grid electrodes of three-unit electron gun members 11a, 11b and 110, are used first and second supporting stripmember s 12 and 13 as shown in FIGS. 3A and 3B. The first supporting stripmembers 12 are utilized to interconnect grid electrodes maintained at thesame potential, that is the third grid electrodes 18a, 18b and the fourth grid electrodes 19a, 19b and 19c; andthe fifth grid electrodes 20a, 20b and Mia, respectively. Since respective strip members have the same construction, astrip member 12 utilized tointerconnect the third, grid electrodes 18a, 18b and 18c, will be described as a typical one with reference to FIG. 3A. A flat metal strip is shaped to have three arcuate portions 121 conforming to portions of the outertsur- .faces of the respective third grid electrodes 18a, '18band 18c with their arcuate portions contacted to theouter surfaces of the electrodes. Similarly the fourth grid electrodes 19a, 19b and 19c and the fifth grid electrodes 20a, 20b and 200 are connected together by respective strip members 12 0f the same construction. Supporting strip members 13 of the second type are utilized to interconnect electrodes which are notnecessarily at the same potential, that is the first grid electrodes 16a,

16b and 16c; and the second grid electrodes 17a, 17b and 170. For example, the strip member 13 adapted to interconnect the first grid electrodes 16a, 16b and 160 comprises a supporting arc segment 13b for the first grid electrode 16b at the center which is formed by bending a flat metal strip to have an arcuate central portion 13b, conforming to a portion of the outer periphery of the electrode 16b and outwardly extending projections 13b on the opposite edges of the central portion 13b,.

The supporting element 13a for the left-hand first grid electrode 16a is formed by bending a flat metal strip to have an arcuate portion 13a, conforming to a portion of the outer periphery of the electrode 16a and an outwardly extending projection 13a, provided on the inner edge of the arcuate portion 15a to confront one of the projections 115b,. Similarly the supporting element 13c for the left-hand first grid electrode 160 is formed with an arcuate portion 13c and outwardly extending projection 130, on one edge thereof.

Two of such second supporting members each comprising three supporting elements 13a, 13b and 130 are used to interconnect the first grid electrodes 16a, 16b and 16c. More particularly, as shown in FIG. 48, two supporting strip members are applied to clamp the first grid electrodes 16a, 16b and 160 between their opposed bent portions 1311,, 13b and 130,, respectively, and these portions are welded to the outer surface of the grid electrodes.

Likewise each of the second grid electrodes is secured by using supporting strip members 13 of the second type.

The first grid electrodes 16a, 16b and 16c, the second grid electrodes 17a, 17b and 170, respectively interconnected by the supporting strip members 13 of the second type, the third grid electrodes 18a, 18b and 180, the fourth grid electrodes 18a, 19b and 190 and the fifth grid electrodes 20a, 20b and 20c, respectively interconnected by the supporting strip members 12 of the first type are mounted on a suitable jig, not sown, At this time, as shown in FIG. 3B projections 13:1 and 130 of the supporting strip elements 13a and 13c for the outside first grid electrodes 16a and 160 are disposed to confront to projections 12b of the supporting strip element 13b for the central first grid electrode 16b with a proper spacing.

Projections 13a, and 13b positioned between the left-hand electron gun member 11a and the central electron gun member 11b are fused to glass insulating rods 14. In the same manner, projections 13b and 130, positioned between the central electron gun member 11b and the right-hand electron gun member He are also fused to glass insulating rods 14. Thus, as shown in FIG. 4B, a total of four such glass rods 14 are used to interconnect three unit electron gun members into a unitary assembly. Since bent projections 122 of the first supporting strip member 12 are flexible the spacing between electrodes of the third grid electrodes 18a, 18b 18c; of the fourth grid electrodes 19a 19b, 19c; and of the fifth grid electrodes 20a, 20b and 200 can be adjusted when these electrodes assemblies are mounted on the jig. Further, as the molten glass of the rods14 flows into the notches 123 provided at the outer edges of respective projections 122, respective grid electrodes are interconnected firmly, as shown in FIG. 4A.

A convergence electrode 15 is secured to three electron gun members l'la 11b and 110 which are interconnected as above described adjacent their fifth grid electrodes 20a, 20band 200. As shown in FIGS. 2 and 5, the convergence electrode 15 may be a bottomed cylinder of circular or rectangular cross section. The bottom 151 of the cylinder is provided with three cylindrical projections 152a 152b, and l52c of small height, the end surfaces of these projections being perpendicular to the axes Sa, Sb and Se of the electron gun members 11a 11b and 11c. At the center of these cylindrical projections 152a, 152b and 152:: are provided perforations 153a, 153b and 153c for passing electron beams, and these projections are snugly received in the fifth grid electrodes 20a, 20b and 20c, respectively. Thereafter, these projections are welded to corresponding grid electrodes 20a, 20b, and 20c, respectively. Thereafter, these projections are welded to corresponding grid electrodes. If desired, the upper edges of thefifth grid electrodes may be welded to the bottom 151 of the convergence electrode 15 directly or through suitable connecting members (not shown).

The convergence assembly includes two pairs of convergence electrodes 154a and 154:: corresponding to the perforation 153a and 1534' respectively, and a magnetic shield cylindrical member 1541; corresponding to the center perforation 1519b.

As shown in FIG. 1 cathode electrodes 2la 21b and 21c are mounted on the first grid electrodes 16a, 16b and 160, respectively of electron gun members 11a, 11b and 1 1c As above described, since in the in-line type triple electron gun assembly 10, three electron gun members 11a, 11b and are firmly bonded to the convergence electrode, they are maintained in correct relative positions so that electron beams emanated from respective cathode electrodes of electron gun members 11a 11b and 11c are accurately directed to perforations 153a, l63b and 153c of the convergence electrode 15 after passing through respective grid electrodes.

Further, since respective grid electrodes of three gun members 11a, 11b and 11c are firmly bonded into a unitary structure 10 by means of the first and second supporting strip members 12 and 13 and insulating rods 14, the unitary structure has sufficient mechanical strength and can withstand thermal deformation.

Flexibility of bent projections 122 of the first supporting strip member 12 permits slight differences in the spacing between three juxtaposed electron gun members 1 1a, 11b and 1 10.

Although the foregoing embodiment has been described in connection with a triple electron gun assembly wherein the first and second grid electrodes are not necessarily maintained at the same potential and wherein the third to fifth electrodes are maintained at the same potential, it will be understood that the invention can also be applied to such a triple electron gun assembly wherein the cathode electrodes are not necessarily maintained at the same potential and the first electrodes are maintained at the same potential. In the latter case the first electrodes are supported by the supporting strip members of the first type shown in FIG. 3A. The number of grid electrodes may be different from the illustrated number, five, that is, it may be four, for example.

Thus, this invention provides an improved in-line type triple electron gun assembly wherein various electrode members are firmly joined with high accuracies into a unitary structure so that when the assembly is incorporated into a color-receiving tube it is possible not only to improve its various electric characteristics such as convergence characteristic, allowance of the radial and lateral convergence adjustments but also to decrease soft focusing and noncoincidence of colors, thus improving the quality of the reproduced image. As the bent projection 122 of the supporting strip members 12 has a triangular sectional configuration, it can be firmly bonded with the rod 14 and notch 123 thereof permits the flow of molten glass, thus further improving the bonding strength.

What we claim is:

1. An in-line type triple gun assembly comprising three electron gun members, each of said electron gun members including a plurality of electrodes spaced apart along an axis along which an electron beam passes, axes of said three electron gun members being juxtaposed in a common plane; first and second supporting strip members, said first supporting strip member having outwardly extending projections and two such first supporting strip members clamping therebetween corresponding electrodes of the same potential of said three electron gun members; said second supporting strip member in cluding three strip elements each having at least one outwardly extending projection, and two such second supporting strip members clamping therebetween corresponding electrodes at different potentials of said three unit electron gun members; two pairs of insulating supporting rods, each pair of said insulating supporting rods being positioned between adjacent pairs of said electron gun members along the axes thereof and fused to said outwardly extending projections of said first and second supporting strip members; and a convergence electrode mounted at one end of said three unit electron gun members, said convergence electrode being provided at its bottom with perforations for passing electron beams travelling through said electron gun members.

2. The in-line type triple electron gun assembly according to claim 1 wherein each of said electron gun members comprises first to fifth electrodes, the third to fifth electrodes are maintained at the same potential, first and second electrodes are maintained at different potentials, each pair of said first supporting strip members are secured to respective groups of said third to fifth electrodes and each pair of said second supporting strip members are secured to respective groups of said first and second electrodes of said three unit electron gun members.

3. The in-line type triple electron gun assembly according to claim 1 wherein each of said outwardly extending projections of said first and second supporting strip members is formed with a notch at its outer edge.

4. The in-line type triple electron gun assembly according to claim 1 wherein cylindrical projections are formed at the bottom of said convergence electrode, each of said projections including one of said perforations for passing said electron beams and being received in the outermost electrode of one of said gun members. 

1. An in-line type triple gun assembly comprising three electron gun members, each of said electron gun members including a plurality of electrodes spaced apart along an axis along which an electron beam passes, axes of said three electron gun members being juxtaposed in a common plane; first and second supporting strip members, said first supporting strip member having outwardly extending projections and two such first supporting strip members clamping therebetween corresponding electrodes of the same potential of said three electron gun members; said second supporting strip member including three strip elements each having at least one outwardly extending projection, and two such second supporting strip members clamping therebetween corresponding electrodes at different potentials of said three unit electron gun members; two pairs of insulating supporting rods, each pair of said insulating supporting rods being positioned between adjacent pairs of said electron gun members along the axes thereof and fused to said outwardly extending projections of said first and second supporting strip members; and a convergence electrode mounted at one end of said three unit electron gun members, said convergence electrode being provided at its bottom with perforations for passing electron beams travelling through said electron gun members.
 2. The in-line type triple electron gun assembly according to claim 1 wherein each of said electron gun members comprises first to fifth electrodes, the third to fifth electrodes are maintained at the same potential, first and second electrodes are maintained at different potentials, each pair of said first supporting strip members are secured to respective groups of said third to fifth electrodes and each pair of said second supporting strip members are secured to respective groups of said first and second electrodes of said three unit electron gun members.
 3. The in-line type triple electron gun assembly according to claim 1 wherein each of said outwardly extending projections of said first and second supporting strip members is formed with a notch at its outer edge.
 4. The in-line type triple electron gun assembly according to claim 1 wherein cylindrical projections are formed at the bottom of said convergence electrode, each of said projections including oNe of said perforations for passing said electron beams and being received in the outermost electrode of one of said gun members. 